Jet LF-20, Operating Instructions And Parts Manual, Page: 7 / 20

7
6.2 Extension cords
The use of extension cords is discouraged; try to
position machines near the power source. If an
extension cord is necessary, make sure it is in good
condition. When using an extension cord, be sure to
use one heavy enough to carry the current your
product will draw. An undersized cord will cause a
drop in line voltage resulting in loss of power and
overheating. Table 1 shows correct size to use
depending on cord length and nameplate ampere
rating. If in doubt, use the next heavier gauge. The
smaller the gauge number, the heavier the cord.
Extension Cord Recommended Gauges (AWG)
Amps
Extension cord length *
25
feet
50
feet
75
feet
100
feet 150
feet 200
feet
< 5 16 16 16 14 12 12
5 to 8 16 16 14 12 10 NR
8 to 12 14 14 12 10 NR NR
12 to 15 12 12 10 10 NR NR
15 to 20 10 10 10 NR NR NR
21 to 30 10 NR NR NR NR NR
*based on limiting the line voltage drop to 5V at 150% of the rated
amperes. NR = Not Recommended.
Table 1
7.0 Operation
The following figures show top
cover removed for clarity only. All top covers
must be installed before operating machine.
Failure to comply may cause serious injury.
NOTE: Length of workpiece must be at least 7-
inches. If a shorter piece is required, process a
longer piece, then cut to length.
7.1 Pittsburgh Lock Seam procedure
This machine comes pre-installed with a Pittsburgh
lock roll set, and requires only fence adjustment to
proceed with this operation.
1. Make sure workpiece is free of burrs or twist
from snip cuts.
Twists or bent notches in
material can strike and damage the knife-
edge roll that holds open the pocket of the
Pittsburgh Lock. Flatten such edges before
feeding material.
2. Adjust entry fence, using a straight edge. See
Figure 7-2. Entry fence position determines
width of hammer-over edge. Tighten both nuts
on entry fence.
3. Adjust exit fence as follows: Run a test piece
through and stop machine when workpiece has
reached end of exit table but is still pinched
between the rolls. Move fence into position just
flush or slightly clear of workpiece edge. Exit
fence must not bear pressure against
workpiece under normal circumstances.
Tighten down fence.
4. Hold material against entry fence and slide it
into forming head until machine engages
workpiece and pulls it through. Make sure
workpiece remains against entry fence until its
trailing end is engaged by the rolls.
If a wider or narrower hammer-over edge is desired,
move entry fence to give desired width. Move entry
fence
in to produce wider edge, out to produce
narrower edge. Make sure to move both ends of
entry fence the same distance, keeping it parallel to
front edge of machine’s top plate. See Figure 7-2.
Figure 7-1
Figure 7-2: Pittsburgh Lock Seam setup